In a medium pot, heat the salt, sugar, and coconut milk over a medium-low heat, stirring occasionally. Once the mixture is gently steaming take it off the heat and add the mint leaves. Set aside for 30 minutes.
Place a strainer (sieve) over a medium bowl and pour the coconut milk mixture through it to remove all the mint leaves. Press on the leaves to push out all that goodness. Discard the leaves.
If using the matcha powder (just for colour, really) - place it into a small bowl or mug and gradually stir in a few table spoons of hot water to get a smooth mixture. Pour this into the bowl of coconut milk mixture and stir through. Leave to cool completely.
Pour the cooled popsicle mixture into your popsicle moulds. Drop in the chocolate chips, dividing them between all the wells of the popsicle moulds. Freeze for at least 4 hours (inserting the popsicle sticks about an hour in).
Remove the frozen popsicles from the moulds and place onto a lined baking tray. Place the melted chocolate into a sandwich bag, snip off one tip and use like a piping bag to drizzle over the popsicles - decorating with the cacao nibs immediately after drizzling as the chocolate sets super fast. Place back into the freezer/eat!